# Armin Ronacher

> Armin Ronacher is earendil co-founder; shared Pi governance. Pi on Anchor Terminal, with grades, an about and public profiles.

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- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)
- Updated: 2026-10-28

Earendil co-founder; shared Pi governance.

Armin Ronacher co-founded Earendil, a public benefit corporation that builds open-source software and protocols, with Colin Daymond Hanna. Earendil now develops Pi, the open-source coding agent Mario Zechner brought to the company in 2026. Ronacher created the Flask web framework and spent a decade at Sentry before starting Earendil.

- X: https://x.com/mitsuhiko

## What Armin builds

- [Pi](https://www.anchorterminal.com/tools/earendil-pi.md), graded B, 68.6/100, in Agent harnesses. Pi is an open-source terminal coding agent from Earendil, run on the owner's machine with any of 15 or more model providers. It has interactive, print, JSON and RPC modes, a TypeScript SDK and a built-in MCP client. Earendil co-founder; shared Pi governance, researched 2026-10-27.

## Works with

- [Colin Daymond Hanna](https://www.anchorterminal.com/people/colin-daymond-hanna/), Earendil co-founder; shared Pi governance
- [Mario Zechner](https://www.anchorterminal.com/people/mario-zechner/), Pi creator and technical lead; Earendil partner/shareholder

## Backed by

- [Accel](https://www.anchorterminal.com/investors/accel/)
- [Balderton Capital](https://www.anchorterminal.com/investors/balderton-capital/)
- [Jan Oberhauser](https://www.anchorterminal.com/investors/jan-oberhauser/)
- [Peter Steinberger](https://www.anchorterminal.com/investors/peter-steinberger/)
- [Vlad Yatsenko](https://www.anchorterminal.com/investors/vlad-yatsenko/)
- [David Cramer](https://www.anchorterminal.com/investors/david-cramer/)
- [Cal Henderson](https://www.anchorterminal.com/investors/cal-henderson/)

## Questions

### Who is Armin Ronacher?

Armin Ronacher co-founded Earendil, a public benefit corporation that builds open-source software and protocols, with Colin Daymond Hanna. Earendil now develops Pi, the open-source coding agent Mario Zechner brought to the company in 2026. Ronacher created the Flask web framework and spent a decade at Sentry before starting Earendil.

### What does Earendil make?

Anchor Terminal lists Pi from Earendil. Pi is an open-source terminal coding agent from Earendil, run on the owner's machine with any of 15 or more model providers. It has interactive, print, JSON and RPC modes, a TypeScript SDK and a built-in MCP client.

### Who has invested in Earendil?

The sources our research read name Accel, Balderton Capital, Jan Oberhauser, Peter Steinberger, Vlad Yatsenko, David Cramer and Cal Henderson.

### How are Armin's tools graded?

Pi is graded B, 68.6 out of 100, on Anchor Terminal's benchmark, which scores every listing against the same checklist.

## Sources

- https://mariozechner.at/posts/2026-04-08-ive-sold-out/
- https://earendil.com/posts/pi-1-0/
- https://mariozechner.at/
- https://x.com/badlogicgames
- https://earendil.com/purpose/
- https://ronacher.eu/
- https://twitter.com/mitsuhiko
- https://www.linkedin.com/in/colindhanna
- https://pi.dev/
- https://www.linkedin.com/company/earendil-works

These are the people building the tools we list, named for their public role in the company or project behind a listing, from public pages, with the date it was researched. They don't work for Anchor Terminal (our own team is on the about page, /about/#author). We show public roles, public profiles and what the listing pages show, nothing private. To correct something, send an about or a photo, or have a page removed, write to privacy@anchorterminal.com.

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